Livestock Susceptibility to Infection with Middle East Respiratory Syndrome Coronavirus

Abstract

Middle East respiratory syndrome (MERS) cases continue to be reported, predominantly in Saudi Arabia and occasionally other countries. Although dromedaries are the main reservoir, other animal species might be susceptible to MERS coronavirus (MERS-CoV) infection and potentially serve as reservoirs. To determine whether other animals are potential reservoirs, we inoculated MERS-CoV into llamas, pigs, sheep, and horses and collected nasal and rectal swab samples at various times. The presence of MERS-CoV in the nose of pigs and llamas was confirmed by PCR, titration of infectious virus, immunohistochemistry, and in situ hybridization; seroconversion was detected in animals of both species. Conversely, in sheep and horses, virus-specific antibodies did not develop and no evidence of viral replication in the upper respiratory tract was found. These results prove the susceptibility of llamas and pigs to MERS-CoV infection. Thus, the possibility of MERS-CoV circulation in animals other than dromedaries, such as llamas and pigs, is not negligible.

Co‐localization of Middle East respiratory syndrome coronavirus ( MERS ‐CoV) and dipeptidyl peptidase‐4 in the respiratory tract and lymphoid tissues of pigs and llamas

“…All paraffin blocks and fresh tissue samples used in the present work were obtained from a previous experimental study demonstrating that llamas and pigs were susceptible to MERS‐CoV infection (Vergara‐Alert et al., ). Briefly, 2‐month‐old pigs and 6–8‐month‐old llamas were intranasally inoculated with 10 7 50% tissue culture infective dose (TCID50) MERS‐CoV in 3 ml saline solution.…”

“…The receptor binding domain (RBD) of the S‐protein mediates viral entrance through binding dipeptidyl peptidase‐4 (DPP4, also known as CD26), a serine protease expressed on the surface of many cell types (Raj et al., ). The tissue distribution of DPP4 has been described in some animal species, including dromedary camels, bats, pigs, llamas, sheep and horses (Vergara‐Alert et al., ; Widagdo et al., , ). However, although DPP4 is decisive for MERS‐CoV entry in vitro (Raj et al., ; Chan et al., ), the role of the protein in determining tissue tropism with regards to MERS‐CoV pathogenesis in vivo has not been fully elucidated.…”

“…However, although DPP4 is decisive for MERS‐CoV entry in vitro (Raj et al., ; Chan et al., ), the role of the protein in determining tissue tropism with regards to MERS‐CoV pathogenesis in vivo has not been fully elucidated. MERS‐CoV antigen has been demonstrated in nasal epithelial cells expressing DPP4 (Haagmans et al., ; Vergara‐Alert et al., ). However, no double staining studies to detect potential co‐localization of both antigens were reported until very recently.…”

“…Taking into account that a number of animal species may potentially act as reservoirs for MERS‐CoV (Vergara‐Alert et al., ), it is important to establish if DPP4 determines or not tissue tropism with regards to viral pathogenesis in vivo . Moreover, if the ciliary loss is a particular finding of dromedary camels infected with MERS‐CoV or may also affect other susceptible species is not known.…”

An opportunistic Pathogen Afforded Ample Opportunities: Middle East Respiratory Syndrome Coronavirus

“…evidence. [54][55][56] In addition, alpacas have been found to be naturally infected. [63] Virus genetically detected or biologically cultured from humans is nearly identical to that isolated from camels and, in some instances, has been used to identify transmission routes.…”